5G Spectrum

Worldwide allocation of 5G spectrum as on December 2020. Source: Qualcomm 2020a, slide 2.
Worldwide allocation of 5G spectrum as on December 2020. Source: Qualcomm 2020a, slide 2.

5G spectrum spans a wide range from 410 MHz to 52600 MHz. The high end of the spectrum falls in the millimeter range, which is novel to 5G. With its high bandwidth, it enables high-throughput, ultra-low-latency applications.

Not all frequencies in this range are used by 5G. 5G defines a number of operating bands within which 5G services can be offered. These frequencies have been selected based on suitability and availability. The bands should not overlap with non-5G systems such as military, maritime, and satellite communication systems.

Both licensed and unlicensed spectrum can be used in 5G. 5G can share 4G's licensed spectrum and Wi-Fi's unlicensed spectrum.

Successful worldwide deployment of 5G requires that countries agree on a common set of bands. Good agreement was reached in November 2019 at WRC-19.

Discussion

  • Which are the main spectrum bands allocated for 5G?
    Low, mid and high-band spectra in 5G. Source: Qualcomm 2020a, slide 4.
    Low, mid and high-band spectra in 5G. Source: Qualcomm 2020a, slide 4.

    The standard defines two frequency ranges: FR1 (410-7125 MHz) and FR2 (24250-52600 MHz).

    NR operating bands are defined within each range. While FR1 bands are either in FDD, TDD, SDL or SUL, FR2 bands can operate only in TDD. Supplementary Downlink (SDL) and Supplementary Uplink (SUL) are modes that allow only downlink or uplink in those bands. SDL and SUL are meant to provide additional capacity.

    In practice, industry looks at 5G spectrum in terms of low-band (600-700 kHz), mid-band (3-5 GHz) and high-band (26-100 GHz). Others simply refer to FR1 as "sub-6 GHz" band and FR2 as mmWave band.

    Specifically, n78 (3300-3800 MHz) TDD band is globally harmonized and will be the primary 5G band. It's a subset of n77 (3300-4200 MHz).

  • How are the 5G bands and frequencies named or numbered?
    Release 15 5G operating bands in frequency ranges FR1 and FR2. Source: ETSI 2020a, sec. 5.2.
    Release 15 5G operating bands in frequency ranges FR1 and FR2. Source: ETSI 2020a, sec. 5.2.

    Operating bands are named with prefix "n" to signify New Radio. In Release 16, FR1 has 49 different bands from n1 to n96. FR2 has 5 bands n257-n261.

    In each band, the standard gives identifying numbers to frequencies. There are two sets of numbers:

    • NR Absolute Radio Frequency Channel Number (NR-ARFCN): Used in signalling to identify reference frequencies. Channel raster is a subset of reference frequencies used to identify RF channel position in uplink and downlink.
    • Global Synchronization Channel Number (GSCN): Used for synchronization. Synchronization raster is specified by GSCN and indicates frequency positions of the Synchronization Signal Block (SSB). GSCN has a coarser granularity than NR-ARFCN and therefore should enable a UE do a faster cell search.
  • Could you describe the 5G NR channel bandwidth?
    5G NR channel bandwidth and transmission bandwidth. Source: ETSI 2020b, fig. 5.3.1-1.
    5G NR channel bandwidth and transmission bandwidth. Source: ETSI 2020b, fig. 5.3.1-1.

    Each operating band may have one or more BS channel bandwidths. Each BS channel bandwidth supports a single RF carrier in UL or DL. Multiple UE channel bandwidths may be supported within the same BS channel bandwidth.

    One or more resource blocks (RBs) form a UE channel bandwidth or transmission bandwidth. Each RB has 12 subcarriers. Unlike 4G where sub-carrier spacing (SCS) is fixed to 15 kHz, 5G NR allows flexible SCS of 15, 30 or 60 kHz (FR1); and 60 or 120 kHz (FR2).

    Guardbands exist at the edges of the BS channel bandwidth. Standard specifies the minimum guardband for each valid combination of SCS and BS channel bandwidth.

    BS channel bandwidth can take values 5, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90 and 100 MHz (FR1); and 50, 100, 200 and 400 MHz (FR2). However, not all values as valid for all bands. For example, 100MHz in FR1 is valid only for bands n40, n41, n77, n78, n79 and n90.

  • Could you compare FR1 and FR2 operating bands?
    Comparing FR1 and FR2 operating bands. Source: Cavazos 2020, table 2.
    Comparing FR1 and FR2 operating bands. Source: Cavazos 2020, table 2.

    FR1 defines bands in the sub-6 GHz spectrum (although 7125 MHz is the maximum) and FR2 defines bands in the mmWave spectrum. Because of the higher carrier frequencies in FR2, it has a higher maximum bandwidth. Bandwidths include 5-100 MHz (FR1) and 50/100/200/400 MHz (FR2). Correspondingly, valid subcarrier spacing values are also different: 15/30/60 kHz (FR1) and 60/120 kHz (FR2). In FR2, 240 kHz subcarrier spacing is allowed for only SS/PBCH with valid bandwidths 100/200/400 MHz.

    Downlink MIMO differs: 8x8 (FR1) and 2x2 (FR2). FR1 caters for macro cells, high mobility and many users. FR1 bands also experience multipath effects. Higher-order MIMO therefore enable spatial multiplexing and Multi-User MIMO (MU-MIMO). On the other hand, FR2 is for small cells, low mobility and a few users. Multipath effects are less pronounced than in FR1. Lower-order MIMO therefore enables beamforming. These differences imply that spectral efficiency is higher in FR1 than in FR2.

  • What's the suitability of low, mid and high-bands for 5G services?
    Use cases of 5G low-band, mid-band and high-band. Source: Adapted from Reply 2020.
    Use cases of 5G low-band, mid-band and high-band. Source: Adapted from Reply 2020.

    Lower frequencies have better range but offer lower data rates. At mmWave spectrum, we get high data rates but waves can't get through walls, trees or even glass. Thus, there's a tradeoff between coverage and speed. It's therefore good that 5G spans a wide spectrum to suit many different use cases and deployment scenarios.

    Low-band spectrum can offer rural coverage. Strong indoor signals could help connect to IoT devices in smart buildings and underground parking lots.

    High-band spectrum could be ideal for short-range communications in dense urban areas and within buildings. It can cater to many high-value services in retail, healthcare, entertainment, and more. They could involve AR/VR applications. Serving thousands of users in a stadium, critical IoT applications or applications that need ultra low latency are more use cases.

    Mid-band spectrum is a compromise of both low-band and high-band spectra. It could cover large neighbourhoods and even an entire city but probably can't serve rural areas. Smart city services can benefit from it, such as fleet management, transit services and vehicle communications.

  • What are some features that enhance the use of 5G spectrum?

    It's possible for 5G to share 4G spectrum. Called Dynamic Spectrum Sharing (DSS), this is an attractive option for operators who don't have licensed 5G spectrum yet. Instead of statically re-farming the spectrum, DSS allows operators to dynamically migrate more spectrum from 4G to 5G as more 5G users come into the system. DSS requires only a software upgrade.

    Supported since LTE Release 10, Carrier Aggregation (CA) is enhanced in 5G. Multiple carriers within the same band or across bands can be combined to serve a single UE. CA allows operators to achieve better capacity, throughput and coverage in mid-band and high-band spectra. For example, low band FDD with DSS can be used in uplink for better coverage and a high band TDD in downlink for higher throughput and capacity.

    Supported since LTE Release 12, Dual Connectivity (DC) is enhanced in 5G. DC allows a UE to connect to two different cells possibly served by different gNBs. It may be an LTE or 5G cell. Whereas user plane split happens at MAC for CA, it happens at PDCP for DC. It's also possible to combine CA and DC.

  • What's the relevance of unlicensed bands for 5G?
    Example scenarios of using unlicensed spectrum for 5G. Source: Qualcomm 2020b, slide 10.
    Example scenarios of using unlicensed spectrum for 5G. Source: Qualcomm 2020b, slide 10.

    Cellular use of unlicensed spectrum started in LTE. It's variants include LTE Unlicensed (LTE-U), Licensed Assisted Access (LAA) and MulteFire.

    In Release 16, 5G NR-U allowed the use of unlicensed spectrum. In particular, NR-U supports both license-assisted and standalone use of unlicensed spectrum. It supports 5 GHz unlicensed band used by Wi-Fi and LAA. It also opens up unlicensed spectrum in the 6 GHz band. Unlicensed spectrum in the mmWave band is being studied for Release 17.

    Since licensed spectrum is limited, for very high bandwidth applications, aggregating with unlicensed spectrum is an attractive approach. Shared/unlicensed spectrum can enable local/private networks and Industrial IoT applications.

    With Anchored NR-U, operators can employ carrier aggregation with 5G NR or dual connectivity with LTE. In urban hotspots, campuses and malls, this can deliver consistent user experience. With Standalone NR-U, operators will find it easier to deploy private networks.

Milestones

Nov
2015
Harmonization of bands for IMT at WRC-15. Source: Ericsson 2015, slide 4.
Harmonization of bands for IMT at WRC-15. Source: Ericsson 2015, slide 4.

At the World Radiocommunication Conference 2015 (WRC-15), delegates agree on additional spectrum for International Mobile Telecommunications (IMT). This includes C-band that later becomes a globally harmonized spectrum for 5G.

2016
Spectrum evolution from LTE to 5G, including current study items. Source: Szydelko and Dryjanski 2016, table 2.
Spectrum evolution from LTE to 5G, including current study items. Source: Szydelko and Dryjanski 2016, table 2.

Szydelko and Dryjanski publish an evolution of spectrum from LTE to 5G. Spectrum below 6 GHz and mmWave spectrum are being considered for 5G. For CA, 700 MHz is being considered for SDL. This is standardized in Release 16 (July 2020).

Mar
2017
In the US, old 600 MHz TV spectrum re-farmed for LTE and 5G. Source: Qualcomm 2020a, slide 5.
In the US, old 600 MHz TV spectrum re-farmed for LTE and 5G. Source: Qualcomm 2020a, slide 5.

In the US, FCC auctions 600 MHz spectrum currently used by TV stations. This spectrum will be used for LTE and 5G, with the transition expected to take 39 months. In July 2020, it's reported that 99% of the migration is complete.

Sep
2019

Ericsson claims the world's first 5G data call using Dynamic Spectrum Sharing (DSS) in low band FDD. In February 2020, with vendors Ericsson, Huawei and Qualcomm, Vodafone proves Dynamic Spectrum Sharing (DSS) in the low bands 700 MHz and 800 MHz on a non-standalone device. In June 2020, AT&T deploys DSS. Meanwhile, Nokia has claimed that DSS is nothing new to it. Years ago, it achieved 2G-4G DSS in which low-band GSM spectrum was used to expand LTE service.

Nov
2019

At the World Radiocommunication Conference 2019 (WRC-19), delegates meet and agree towards harmonization of 5G spectrum. In particular, 24.25-27.5, 37-43.5, 45.5-47, 47.2-48.2 and 66-71 GHz are identified. This translates to 17.25 GHz of spectrum compared to only 1.9 GHz available before this conference. Of this, 14.75 GHz of spectrum has been harmonized worldwide, reaching 85% of global harmonization. The next meeting will be WRC-23 in 2023.

Jun
2020

Global mobile Suppliers Association (GSA) reports that 97 operators in 17 countries have public licenses to operate 5G service in mmWave spectrum. Of these, 22 operators are already operational with 24.25–29.5 GHz being the most common band.

Jul
2020
Unlicensed spectrum for 5G. Source: Qualcomm 2020a, slide 3.
Unlicensed spectrum for 5G. Source: Qualcomm 2020a, slide 3.

3GPP finalizes Release 16 specifications. This release adds many more bands to FR1. In FR2, n259 (39500-43500 MHz) is added. This release also adds NR-U for operation in unlicensed spectrum.

Oct
2020
Count of operators investing in 5G spectrum bands. Source: GSA 2020, fig. 1.
Count of operators investing in 5G spectrum bands. Source: GSA 2020, fig. 1.

GSA reports that operators are showing most interest in n77 and n78 (mid-band); n257, n258 and n260 (mmWave); and n28 (low-band). GSA website is also the place to track the latest in 5G spectrum news.

Dec
2020

In the US, FCC puts up for auction 280 MHz of spectrum in the range 3.7-3.98 GHz, known as C-band. A successful bidder will likely purchase 100 MHz of contiguous mid-band spectrum. Compared to mmWave, C-band has better propagation properties, making this an important auction for 5G operators.

References

  1. Basile, Massimo. 2018. "Is your network ready for 5G?" RAN World 2018, Rome, October 9. Accessed 2020-12-25.
  2. CableFree. 2020. "5G Frequency Bands & Spectrum Allocations." CableFree, January 17. Accessed 2020-12-25.
  3. Camargos, Luciana. 2019. "WRC-19 strikes a good balance, sets stage for mmWave 5G." GSMA, November 25. Accessed 2020-12-24.
  4. Casaccia, Lorenzo. 2020. "Propelling 5G forward: A closer look at 3GPP Release 16." OnQ Blog, Qualcomm, July 7. Accessed 2020-12-26.
  5. Cavazos, Jessy. 2020. "5G NR: A Step-Function Increase Over 4G LTE." Blog, Keysight Technologies, July 24. Accessed 2021-01-17.
  6. DiMolfetta, David. 2020. "More than 99% of TV stations moved off 600 MHz wireless spectrum – FCC." Market Intelligence, S&P Global, July 14. Accessed 2020-12-28.
  7. Dryjanski, Marcin. 2019. "LTE in Unlicensed Spectrum." Grandmetric, January 7. Updated 2020-04-07. Accessed 2020-12-25.
  8. Ericsson. 2015. "ITU WRC-15 summary." Ericsson, December 14. Accessed 2020-12-26.
  9. Ericsson. 2019. "Breakthrough 5G data call using dynamic spectrum sharing to accelerate nationwide 5G deployments." News, Ericsson, September 4. Accessed 2020-12-25.
  10. Ericsson. 2020. "Carrier aggregation in 5G." Ericsson. Accessed 2020-12-25.
  11. ETSI. 2020a. "TS 138 104: 5G; NR; Base Station (BS) radio transmission and reception." V15.11.0, November. Accessed 2020-12-26.
  12. ETSI. 2020b. "TS 138 104: 5G; NR; Base Station (BS) radio transmission and reception." V16.5.0, November. Accessed 2020-12-26.
  13. Fan, Mingxi. 2016. "5G spectrum sharing brings new innovations." OnQ Blog, Qualcomm, November 17. Accessed 2020-12-25.
  14. Fundarc-Comm. 2019. "The Need for Globally Harmonised 5G Spectrum." Fundarc Communication, February 2. Accessed 2020-12-22.
  15. Gold, Jon. 2020. "FCC's 5G-frequency auction prompts $2 billion in bids on the first day." Network World, IDG Communications, December 9. Accessed 2020-12-25.
  16. Goodwins, Rupert. 2019. "5G New Radio: The technical background." ZDNet, February 1. Accessed 2020-12-25.
  17. GSA. 2020. "5G Spectrum Snapshot October 2020." GSA, October. Accessed 2020-12-28.
  18. Halberd Bastion. 2020. "5G Frequency Bands." Halberd Bastion Pty Ltd. Accessed 2020-12-26.
  19. Horwitz, Jeremy. 2019. "The definitive guide to 5G low, mid, and high band speeds." VentureBeat, December 10. Accessed 2020-12-25.
  20. ITU. 2019. "WRC-19 identifies additional frequency bands for 5G." News, ITU, November 22. Accessed 2020-12-25.
  21. Kuosa, Harry. 2020. "The well-kept secret of 2G-3G-4G-5G Dynamic Spectrum Sharing." Blog, Nokia, May 20. Accessed 2020-12-25.
  22. Malhotra, Dheeraj. 2020. "Carrier Aggregation." NR LTE related tech oriented blog, May 9. Accessed 2020-12-25.
  23. Marek, Sue. 2020. "Dynamic spectrum sharing could be the 5G solution that wireless operators are looking for." furithithmic, Nokia, August 14. Accessed 2020-12-25.
  24. Microwave Journal. 2020. "GSA: 97 Operators Globally Now Hold mmWave Spectrum for 5G." Microwave Journal, June 23. Accessed 2020-12-25.
  25. Murphy, Jeff. 2019. "7 Key Measurement Challenges and Case Studies." Part Two in: 5G Boot Camp, Keysight Technologies, August. Accessed 2021-01-17.
  26. Ofcom. 2016. "UK Report on the outcome of the World Radiocommunication Conference 2015 (WRC-15)." Ofcom, March 16. Accessed 2020-12-26.
  27. Qualcomm. 2016. "5G Spectrum Sharing & Unlicensed Spectrum." Qualcomm, November 16. Updated 2020-09-09. Accessed 2020-12-25.
  28. Qualcomm. 2020a. "Global update on spectrum for 4G & 5G." Qualcomm, December. Accessed 2020-12-25.
  29. Qualcomm. 2020b. "How does unlicensed spectrum with NR-U transform what 5G can do for you?" Qualcomm, June. Accessed 2020-12-28.
  30. Reply. 2020. "Understanding 5G Spectrum Frequency Bands." Reply, June 23. Accessed 2020-12-25.
  31. RF Wireless World. 2020. "5G NR Carrier Aggregation (CA) basics | Carrier Aggregation frequency bands." RF Wireless World. Accessed 2020-12-25.
  32. ShareTechnote. 2020. "5G/NR - FR/Operating Bandwidth." ShareTechnote. Accessed 2020-12-26.
  33. Szydelko, Michal, and Marcin Dryjanski. 2016. "Spectrum Toolbox Survey:Evolution Towards 5G." In: Noguet D., Moessner K., Palicot J. (eds) Cognitive Radio Oriented Wireless Networks. CrownCom 2016. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, vol. 172, pp. 703-714. Springer, Cham. doi: 10.1007/978-3-319-40352-6_58. Accessed 2020-12-28.
  34. T-Mobile. 2020. "The Benefits of a 5G Network on Multiple Spectrum Bands." T-Mobile. Accessed 2020-12-26.
  35. Techplayon. 2019. "Dual Connectivity (DC) Definition, Protocol Architecture, DC and CA Comparison." Techplayon, June 15. Accessed 2020-12-26.
  36. Weissberger, Alan. 2020. "Vodafone tests 5G Dynamic Spectrum Sharing (DSS) in its Dusseldorf lab." Technology Blog, IEEE ComSoc, February 4. Accessed 2020-12-25.

Further Reading

  1. Qualcomm. 2020a. "Global update on spectrum for 4G & 5G." Qualcomm, December. Accessed 2020-12-25.
  2. Qualcomm. 2020b. "How does unlicensed spectrum with NR-U transform what 5G can do for you?" Qualcomm, June. Accessed 2020-12-28.
  3. IEEE Spectrum. 2019. "Unlicensed Spectrum May Be Critical to 5G." IEEE Spectrum, September 5. Accessed 2020-12-25.
  4. Wannstrom, Jeanette. 2013. "Carrier Aggregation explained." 3GPP, June. Accessed 2020-12-25.
  5. ShareTechnote. 2020. "5G/NR - FR/Operating Bandwidth." ShareTechnote. Accessed 2020-12-26.
  6. Marek, Sue. 2020. "Dynamic spectrum sharing could be the 5G solution that wireless operators are looking for." furithithmic, Nokia, August 14. Accessed 2020-12-25.

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Devopedia. 2021. "5G Spectrum." Version 7, June 28. Accessed 2021-06-28. https://devopedia.org/5g-spectrum
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Last updated on
2021-06-28 15:55:37